create sequence test_seq1;

select test_seq1.nextval from dual

insert into table(no, name) values(test_seq1.nextval);

create sequence test_seq2
start with 100
minvalue 0
maxvalue 100
increment by -1

select test_seq2.nextval from dual


select writing_no, writing_title, writing_content, writing_date, writing_hits, refamily, restep, relevel, member_id, rownum
from ( select * from board order by refamily desc, restep asc )
where 

select *
from
	(select writing_no, writing_title, writing_content, writing_date, writing_hits, refamily, restep, relevel, member_id, rownum rnum
	from ( select * from board order by refamily desc, restep asc ))
where rnum > ceil((2-1)*10) and rnum <= floor(2*10)




delete BOARD

SET foreign_key_checks = 0;

ALTER TABLE board
DROP CONSTRAINT board_fk
